With the government teetering on the possibility of a partial shutdown in nine days, President Trump said he would be “totally willing” to allow that to happen if Congress does not fully fund his much-touted wall on the southern border.

“I don’t do anything … just for political gain,” Trump told Politico in an interview published Wednesday. “But I will tell you, politically speaking, that issue is a total winner. People look at the border, they look at the rush to the police, they look at the rock throwers and really hurting three people, three very brave Border Patrol folks — I think that it’s a tremendous issue, but much more importantly, is really needed. So we have to have border security.”

The president said he is “firm” that he get $5 billion for the wall, which he used as a major campaign theme during his presidential run while claiming Mexico would pay for it, setting up a showdown with Democrats leading to the Dec. 7 deadline.

Even more, Trump said the $5 billion would only cover the physical border. “The number is larger for border security,” he said.

He threatened to veto any spending bill that doesn’t include the funding.

Senate Minority Leader Chuck Schumer said Democrats would back $1.6 billion for border security that they negotiated with their Republican colleagues — but not a penny more.

Any delay in funding could interrupt operations for Homeland Security, the Justice Department, the State Department and numerous other government agencies.

“Left to our own devices, the Senate and House could come to an agreement,” Schumer said. “The Republicans are in control of the presidency, the House and the Senate. A shutdown is on their back.”

House Republicans met with Trump at the White House on Tuesday and afterward said they have the president’s back on the matter.

“The president has been very clear that he needs $5 billion to properly secure the border. We need to be there for him and make sure this gets signed,” House Majority Whip Steve Scalise said after the meeting.

Sen. Richard Shelby, the Republican head of the Appropriations Committee, suggested approving the full $5 billion but spreading it out over two years.

The debate is being carried out as a caravan of Central American migrants at the US-Mexico border has been making headlines.